Here it is on Steam.
I did a little diggin' around Salt and Sanctuary after it appeared on Steam last night. First of all, it sounds like the game did pret-ty darned good on PS4:
@darklordjames can't give specific numbers, but we're obviously stupidly happy, and good for a few more games :)— James Silva (@Jamezila) May 12, 2016
Second, don't ask Ska Studios about how the Vita version is doing because they don't know:
"We also unfortunately don’t know details on the Vita port; just that it is being handled by other developer. As soon as we’re able to reveal more, we will surely post about it!"
Huh. That is very weird, isn't it? They don't know where the Vita port is at? Was it like taken by Sony and Ska aren't involved in the port at all?
Very curious. Anyway, it's an awesome Metroidvania platforming open-world action-RPG and you should play it!